Phase wellbore steering

Abstract

A method of steering a drilling operation of a well using acoustic measurements. The method includes obtaining, using a central processing unit (CPU), a clean-wet matrix line for the well, where the clean-wet matrix line includes a number of normal compressional values, obtaining, using the CPU, the acoustic measurements from at least one logging while drilling tool at a current depth of the drilling operation, where the acoustic measurements include a compressional to shear velocity ratio and a delta-T compressional measurement, and determining, using the CPU, a current phase of the drilling operation by comparing the acoustic measurements to the clean-wet matrix line. The method further includes, in response to determining that the current phase is not a target phase, generating an updated well trajectory for steering the drilling operation toward the target phase and adjusting the drilling operation using the updated well trajectory.

1. A method of steering a drilling operation of a well using acoustic measurements, comprising:
 obtaining, using a central processing unit (CPU), a clean-wet matrix line for the well, wherein the clean-wet matrix line comprises a plurality of normal compressional values; 
 obtaining, using the CPU, the acoustic measurements from at least one logging while drilling tool at a current depth of the drilling operation, wherein the acoustic measurements comprise a compressional to shear velocity ratio and a delta-T compressional measurement; 
 generating an earth model using a plurality of subsurface measurements; 
 updating the earth model using the compressional to shear velocity ratio and the delta-T compressional measurement to obtain an updated earth model; 
 determining, using the CPU, a current phase of the drilling operation by comparing the acoustic measurements to the clean-wet matrix line; 
 in response to determining that the current phase is not a target phase, generating, using the updated earth model, an updated well trajectory for steering the drilling operation toward the target phase; and 
 adjusting the drilling operation using the updated well trajectory. 
 
     
     
       2. The method of  claim 1 , wherein the target phase is an oil phase, and wherein the current phase is a transition phase. 
     
     
       3. The method of  claim 2 , wherein the updated well trajectory steers the drilling operation downward toward the oil phase. 
     
     
       4. The method of  claim 1 , wherein the current phase is determined based on a deviation of the compressional to shear velocity ratio and the delta-T compressional measurement from the clean-wet matrix line. 
     
     
       5. The method of  claim 1 , wherein the at least one logging while drilling (LWD) tool comprises a full quadrapole shear LWD tool. 
     
     
       6. The method of  claim 1 , wherein the well is a horizontal well. 
     
     
       7. A system for steering a drilling operation of a well using acoustic measurements, comprising:
 at least one logging while drilling tool configured to obtain the acoustic measurements at a current depth of the drilling operation, wherein the acoustic measurements comprise a compressional to shear velocity ratio and a delta-T compressional measurement; 
 a phase tool configured to:
 obtain a clean-wet matrix line for the well, wherein the clean-wet matrix line comprises a plurality of normal compressional values; 
 generate an earth model using a plurality of subsurface measurements; 
 update the earth model using the compressional to shear velocity ratio and the delta-T compressional measurement to obtain an updated earth model; 
 determine a current phase of the drilling operation by comparing the acoustic measurements to the clean-wet matrix line; 
 in response to determining that the current phase is not a target phase, generate, using the updated earth model, an updated well trajectory for steering the drilling operation toward the target phase; and 
 
 a controller configured to adjust the drilling operation using the updated well trajectory. 
 
     
     
       8. The system of  claim 7 , wherein the target phase is an oil phase, and wherein the current phase is a transition phase. 
     
     
       9. The system of  claim 8 , wherein the updated well trajectory steers the drilling operation downward toward the oil phase. 
     
     
       10. The system of  claim 7 , wherein the current phase is determined based on a deviation of the compressional to shear velocity ratio and the delta-T compressional measurement from the clean-wet matrix line. 
     
     
       11. The system of  claim 7 , wherein the at least one logging while drilling (LWD) tool comprises a full quadrapole shear LWD tool. 
     
     
       12. The system of  claim 7 , wherein the well is a horizontal well. 
     
     
       13. A computer readable medium storing instructions for steering a drilling operation of a well using acoustic measurements, the instructions when executed causing a processor to:
 obtain a clean-wet matrix line for the well, wherein the clean-wet matrix line comprises a plurality of normal compressional values; 
 obtain the acoustic measurements from at least one logging while drilling tool at a current depth of the drilling operation, wherein the acoustic measurements comprise a compressional to shear velocity ratio (VPVS) and a delta-T compressional measurement (DTCO); 
 generate an earth model using a plurality of subsurface measurements; 
 update the earth model using the compressional to shear velocity ratio and the delta-T compressional measurement to obtain an updated earth model; 
 determine a current phase of the drilling operation based on a deviation of the acoustic measurements from the clean-wet matrix line; 
 in response to determining that the current phase is not a target phase, generate, using the updated earth model, an updated well trajectory for steering the drilling operation toward the target phase; and 
 adjust the drilling operation using the updated well trajectory. 
 
     
     
       14. The computer readable medium of  claim 13 , wherein the target phase is an oil phase, and wherein the current phase is a transition phase. 
     
     
       15. The computer readable medium of  claim 14 , wherein the updated well trajectory steers the drilling operation downward toward the oil phase. 
     
     
       16. The computer readable medium of  claim 13 , wherein the at least one logging while drilling (LWD) tool comprises a full quadrapole shear LWD tool. 
     
     
       17. The computer readable medium of  claim 13 , wherein the well is a horizontal well.